• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 20
  • 20
  • 20
  • 18
  • 14
  • 12
  • 7
  • 7
  • 7
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Test and evaluation of meshdynamics 802.11 multi-radio mesh modules in support of coalition riverine operations

Russo, Joseph Anthony 06 1900 (has links)
The Coalition Operating Area Surveillance and Targeting System (COASTS) program is a joint project between the Naval Postgraduate School and the Royal Thai Armed Forces (RTARF). The program focuses its research on command, control, communications, computers, intelligence, surveillance and reconnaissance (C4ISR) uses for commercial-off-the-shelf (COTS), state-of-the-art, rapidly scaleable airborne and ground communications equipment, including various wireless network technologies. This research is being conducted in partnership with the RTAF to develop a network and associated devices and applications that potentially may help suppress drug trafficking in the northern Thailand border regions. Commensurately, the U.S. Navy is taking the Global War on Terror (GWOT) lead in coalition Maritime Security Operations and riverine warfare operations. With formation of the new Naval Expeditionary Combat Command (NECC), and its new Riverine Warfare Group, the Navyâ s role takes effect starting in January 2007, and could benefit from this research. This thesis focuses on testing and evaluating the overall performance of the MeshDynamics Multiple-Radio Mesh Modules, operating in the 802.11 wireless frequency spectrum. These modules are key building blocks of meshed networks that provide coverage over an area where riverine and coastal operations are being conducted. The network provides an information source and communications backbone for maritime, ground, and air assets. / US Navy (USN) author.
2

Performance analysis of IEEE 802.11A signals under different operational environments

Chan, Hsiung Wei Roy 09 1900 (has links)
Approved for public release, distribution is unlimited / With the rapid employment of wireless networks commercially, the military is seeking viable solutions for providing high-speed wireless network throughout the battle space. The IEEE 802.11a wireless LAN presents an attractive solution pro-viding up to 54 Mbps data-link bandwidth. Moreover, it operates in the less congested 5-GHz U-NII band and possesses more operating channels. This research implemented two prototype systems using low-cost commercially available hardware. The Cisco Ai-ronet 1400 wireless bridge and the Proxim Tsunami MP. 11a wireless system were chosen for their superior specifications and for their reputation of being market leaders in IEEE 802.11 wireless products. The performances of the prototype systems were evaluated in three operational environments (land, water and vegetation). The data collected were then compared to the theo-retical performance. / Civilian, Ministry of Defense, Singapore
3

Wireless tool kit for hand held devices

Baalaji, Venkateshwaraiyer S. 09 1900 (has links)
Approved for public release; distribution is unlimited / Wireless networks can be broadly classified into two types - infrastructure based networks and ad hoc networks. The former uses fixed base stations (infrastructure) which are responsible for coordinating communication between the mobile hosts (nodes). These base stations are interconnected by wired back bones, where as mobile nodes communicate with the base station through the wireless media. The latter one consists of mobile nodes which communicate with each other through wireless medium without any fixed infrastructure. Hence there is no centralized infrastructure that takes care of the routing of information among the participants in the network. There has been a growing interest in ad hoc network in recent years as mobile devices have become more powerful and are capable of processing data like their desktop counterparts. When such a capability is available these devices should be able to share information among them without reliance on existing network infrastructure. Mobile devices are self configurable into either infrastructure or ad hoc mode. Protocols and software have been developed to enable mobile devices to connect to an infrastructure node, where as the same is not the case in the ad hoc environment. Host mobility causes frequent and unpredictable topological changes in a wireless environment. Finding and maintaining routes in ad hoc networks is a non trivial task. This thesis will develop software components that will enable communication in an ad hoc network. These components could be used to build collaborative services in such and ad hoc (802.11) wireless environment. / Major, Indian Air Force
4

Denial of service vulnerabilities in IEEE 802.16 wireless networks

Boom, Derrick D. 09 1900 (has links)
Approved for public release; distribution is unlimited. / The Institute of Electrical and Electronics Engineers' new 802.16 standard is set to revolutionize the delivery of Broadband Wireless Access (BWA), much as the 802.11 "Wi-Fi" standard transformed wireless access to Local Area Networks. The standard describes a set of Medium Access Controls (MAC) and Air Interfaces that cover a broad range of broadcast frequencies and applications. As a result, manufacturers are developing 802.16 compliant equipment for high speed point-to-point circuits and point-to-multipoint circuits dubbed Wireless Metropolitan Area Networks (WMANs). These networks can span several miles and contain hundreds of subscribers. Shortly after 802.11 "Wi-Fi" systems became widespread, several serious Denial of Service (DoS) vulnerabilities inherent to the standard were discovered. This thesis examines the MAC layer of the 802.16 standard to determine whether these types of denial of service vulnerabilities are also present in the new standard. Also examined are vulnerabilities that may be unique to the 802.16 standard. / Lieutenant, United States Navy
5

IEEE 802.16 Commercial Off The Shelf (COTS) technologies as a compliment to Ship To Objective Maneuver (STOM) communications

Munoz, Ramon J., Guice, Robert J. 09 1900 (has links)
Approved for public release; distribution is unlimited. / This research evaluates the IEEE 802.16 standards and technologies that are currently being developed in the commercial sector. The robust capability of this standard lends itself potentially to numerous military applications. This research explores how this technology might address the shortcomings of existing military radio and data systems; specifically, with respect to the issues surrounding the Ship to Objective Maneuver (STOM) communications. The intent of this research is to provide recommendations on the necessary 'adapt from COTS' changes for this technology to address STOM networking requirements. This research includes discussions on the military requirements for an IEEE 802.16 adapted waveform. The requirements are for the IEEE 802.16 'adapt from COTS' are derived from researched on the Concept of Employment for STOM operations and the specification of the Joint Tactical Radio Systems (JTRS) Wideband Networking Waveform (WNW). These discussions offer an illustration of the complex networking demands the COTS adapted systems would need to address. Through detailed exploration of the current IEEE 802.16 standards and implementation testing with pre-standard IEEE 802.16a equipment, we were able to make recommendations on the COTS adaptations necessary to make IEEE 802.16 suitable as a complimentary technology within the STOM scenario. / Captain, United States Marine Corps
6

Denial of service attacks on 802.1X security protocol

Ozan, Orhan 03 1900 (has links)
Approved for public release, distribution unlimited / Wireless Local Area Networks (WLANs) are quickly becoming popular in daily life. Users are adopting the latest technology to save time and costs. In addition, WLANs are providing high-speed network access to the users. There are security concerns with WLANs that must be considered when deploying them over critical infrastructure, such as military and administrative government LANs. The IEEE 802.11 wireless standard specifies both an authentication service and encryption protocol, but research has demonstrated that these protocols are severely flawed. The IEEE has established a new workgroup, the IEEE 802.11i, to address all the security vulnerabilities of the 802.11 security protocol. The workgroup proposed using the IEEE 802.1X Port-Based Network Access Control Standard as an interim measure to meet the security requirements of the WLANs and to maintain the confidentiality, authenticity, and availability of the data until the workgroup is finished with the new specifications. Using an open-source test-bed for evaluating DoS attacks on WLANs, this research demonstrates four different DoS attacks that verify the weaknesses of the IEEE 802.1X protocol. Solutions are provided to mitigate the effects of such DoS attacks. / Lieutenant Junior Grade, Turkish Navy
7

Developing a Fly-Away-Kit (FLAK) to support Hastily Formed Networks (HFN) for Humanitarian Assistance and Disaster Relief)

Lancaster, David D. 06 1900 (has links)
This research discusses developing a FLy-Away-Kit (FLAK) to support the forming of Hastily Formed Networks (HFNs) in remote areas in support of Humanitarian Assistance and Disaster Relief (HA/DR) operations. The initial focus will be on the requirements, situation, area of operations and mission. Different definitions and perspectives emerge when an individual mentions HFNs, HA/DR and Complex Humanitarian Disasters (CHDs). It is the author's intention to define and describe both a HFN and a CHD, in order to justify the need for the FLAK. This process will also define the requirements for the FLAK as well as facilitate processes for ensuring those requirements are met. The personnel responding to the attacks of September 11, 2001 and the December 26, 2004 Southeast Asia Tsunami suffered Command and Control (C2) and information challenges. Even more challenges are being currently addressed by Homeland Defense, Maritime Domain Awareness, and Non-Governmental Organizations (NGOs) abroad. From the top down, levels of administration are developing new plans, procedures, and organizations that will improve the security and communication processes of our nation. A global, broadband, rapidly deployable network node complete with Internet reachback, voice, data, and video capability is of the utmost importance to enable C2 and Network Centric Operations (NCO). Undoubtedly, commercial and military organizations, traditional or new, will greatly benefit from this capability. The U.S. DoD is particularly interested in improving interaction, coordination, communications, and operations when DoD and other entities respond simultaneously to natural or man-made CHD's.
8

Performance analysis of M-QAM with Viterbi soft-decision decoding

Manso, Rogerio C. 03 1900
Approved for public release; distribution is unlimited / This thesis derives design tools for determining and improving performances of communication links that use M - QAM coherent demodulators associated with Viterbi soft-decision decoding (SDD) in Additive White Gaussian Noise (AWGN) and Nakagami-m channels. Performance analyses for 16-QAM, 64-QAM, QPSK and BPSK associated with up to three convolutional codes, including the one used by the IEEE 802.11a standard and the dual-k code, are presented as practical applications. The main tools relate to the analytical derivation of upper bounds of the probability of bit error (Pb) for any M -ary coherent demodulator followed by SDD, a methodology for improving an upper bound of Pb tightening it to realistic data, and the obtaining of the specific ( ) d b spectrum for any convolutional code intended to operate with a certain M-symbol modulation. All derivations involve statistical considerations over the AWGN and Nakagami-m channels, as well as in-depth analyses of modulator constellations. The tools and models developed can provide great optimization to bandwidth-limited system designs that require high data rates, especially the wireless ones. Consequently, they have great application to many fields of digital communications, such as cellular telephony, wireless networking, satellite links, ship-to-shore and ship -to-ship communications. / http://hdl.handle.net/10945/1090 / Lieutenant Commander, Brazilian Navy
9

Collaborative services in an ad hoc wireless network

Baalaji, Venkateshwaraiyer S. 09 1900 (has links)
Approved for public release; distribution is unlimited. / Wireless networks can be broadly classified into two types - infrastructure based networks and ad hoc networks. The former uses fixed base stations (infrastructure) which are responsible for coordinating communication between the mobile hosts (nodes). These base stations are interconnected by wired back bones, where as mobile nodes communicate with the base station through the wireless media. The latter one consists of mobile nodes which communicate with each other through wireless medium without any fixed infrastructure. Hence there is no centralized infrastructure that takes care of the routing of information among the participants in the network. There has been a growing interest in ad hoc network in recent years as mobile devices have become more powerful and are capable of processing data like their desktop counterparts. When such a capability is available these devices should be able to share information among them without reliance on existing network infrastructure. Mobile devices are self configurable into either infrastructure or ad hoc mode. Protocols and software have been developed to enable mobile devices to connect to an infrastructure node, where as the same is not the case in the ad hoc environment. Host mobility causes frequent and unpredictable topological changes in a wireless environment. Finding and maintaining routes in ad hoc networks is a non trivial task. This thesis will develop collaborative services in an ad hoc (802.11) wireless environment. / Major, Indian Air Force
10

Network coding for multi-user wireless networks /

Nguyen, Dong Van. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 143-149). Also available on the World Wide Web.

Page generated in 0.0957 seconds